At present, magnetic transmission is utilized to carry out non-contact transmission in many fields. One of the magnetic transmission structures is called rotary magnetic field structure, where the magnetic transmission is carried out through two columnar magnetic members which are spaced at a certain distance to rotate in parallel. This kind of magnetic transmission structure is introduced in the Chinese patent 001184423  <Manufacturing Method for Magnetic Transmission System of Adjustable Curtain in Hollow or Double-Layer Glass> and the U.S. patent with the patent number U.S. Pat. No. 6,837,295 <MAGNETIC TRANSMISSION FOR AN ADJUSTABLE CURTAIN DISPOSED IN A DOUBLE PANE WINDOW>. It can be seen from the actual use that since the magnetic field directions of the two single columnar magnetic members are both radial, the transmission cycle with the torque value increases from zero to the max appear twice in one circle of rotary transmission, which sometimes leads to a large bounce in the transmission. This phenomenon is particularly obvious during large-torque transmission at low speed which limits the application range of the structure. Later, in order to overcome this defect, a magnetic transmission group composed of multiple radial magnetic fields is disclosed in the Chinese patent application 201020275394.9 <A Rotary Magnetic Transmission Structure>, and the magnetic field direction of each magnet and the magnetic field direction of an adjacent and coaxial magnet spread to form an angle ranging from 45 degrees to 60 degrees. As proven in practice, an unstable shaking phenomena may still exist during transmission in this structure.